Preheat Proportional Valve with Return Water Control v51 - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

Controller Tool Help

Johnson Controls
Product name
Controller Configuration Tool
Document type
User Guide
Document number
Revision date
Important: As of Release 5.1, the Preheat Proportional Valve with Return Water Control v51 module replaces the Preheat Proportional Valve with Return Water Control v50 module.

The Preheat Proportional Valve with Return Water Control module controls a proportional valve for preheat. The module can be configured for DA-T, RA-T, ZN-T, or PH-T. The proportional valve is modulated to control the configured Process Variable. If the return water temperature falls below the Low Limit Setpoint, the valve opens beyond the current control position (maximum 100%) to warm up the return water temperature. The module has temperature control, low limit control, and protection modes such as Low OA Temperature based on OA Temperature. In addition to the proportional valve, this module controls a circulating pump. This module also incorporates tracking the overridden value of the actual output object (AO, PAO). The module resets the PIDs to default tuning parameters if the Reset PID Tuning input is not Normal.

This module provides a second output that incorporates lead compensation to control devices. This function attempts to remove some of the dynamics of the control loop. This process results in forward-looking predictions and speeds up controller responses. The effect is similar to adding derivative action to the controller. Lead compensation is incorporated into most zone temperature control processes where oversized or nonlinear valves might be applied. For more information on the Lead Compensator block, see Lead Compensator in the Control category of the Logic section.

You can view and modify the modules in this group’s logic.